DATASHEET
ISL9021A
FN7845
Rev 3.00
December 20, 2012
250mA Single LDO with Low IQ, Low Noise and High PSRR LDO
The ISL9021A is a single LDO, which provides high
performance, low input voltage and high PSRR. It delivers
guaranteed continuous 250mA load current and is stable with
1µF to 4.7µF of output capacitance (±30%) with an ESR range
of 5m to 400m.
Features
The input voltage range for the ISL9021A is between 1.5V to
5.5V and the output voltage comes in many fixed voltage
options with ±1.8% accuracy over-temperature, line and load
ranges. The ISL9021A has typical PSRR of 75dB @ 10kHz and
50dB @ 1MHz.
• Output voltage range: 1.2V to 3.3V
The reverse current protection feature prevents current from
flowing back to the power source when the output voltage is
pulled higher than the input.
• Stable with 1µF to 4.7µF output capacitance (±30%) with an
ESR range of 5m to 400m
The ISL9021A is offered in tiny 4-bump 0.975mmx1.155mm
WLCSP and 1.6mmx1.6mm 6 Ld µTDFN packages.
• Soft-start limits input current surge during enable
Related Literature
• -40°C to +85°C operating temperature range
• See FN6867, ISL9021 “250mA Single LDO with Low IQ, Low
Noise and High PSRR LDO”
• Available in 0.975mmx1.155mm 4-bump WLCSP package
and 1.6mmx1.6mm 6 Ld µTDFN
• High performance LDO with 250mA guaranteed continuous
output current
• Input voltage range: 1.5V to 5.5V
• High PSRR: 75dB @ 10kHz, 50dB @ 1MHz
• Low quiescent current: 35µA
• Dropout voltage: 1.8V
150
250
mV
160
°C
20
°C
VIN = 4.5V, VO = 3.3V @ 1kHz
60
dB
VIN = 4.5V, VO = 3.3V @ 10kHz
75
dB
VIN = 4.5V, VO = 3.3V @ 1MHz
50
dB
8.5*VO
µVRMS
Thermal Shutdown Hysteresis
AC CHARACTERISTICS
Ripple Rejection (Note 8)
VIN = 4.2V, TA = +25°C, BW = 10Hz to 100kHz, IO = 10mA
Output Noise Voltage (Note 8)
DEVICE START-UP CHARACTERISTICS
Device Enable Time
tEN
Time from assertion of the EN pin to when the output voltage
reaches 95% of the VO (nom)
LDO Soft-start Ramp Rate
tSSR
Slope of linear portion of LDO output voltage ramp during start-up
FN7845 Rev 3.00
December 20, 2012
250
600
µs
30
60
µs/V
Page 5 of 12
ISL9021A
Electrical Specifications
TA = -40°C to +85°C; VIN = (VO + 0.5V) to 5.5V with a minimum VIN of 1.5V; CIN = 1µF; CO = 1µF. Boldface
limits apply over the operating temperature range, -40°C to +85°C. (Continued)
PARAMETER
SYMBOL
MIN
(Note 10)
TEST CONDITIONS
TYP
MAX
(Note 10)
UNIT
0.4
V
EN LOGIC CHARACTERISTICS
Input Low Voltage
VIL
Input High Voltage
VIH
Input Leakage Current
1.1
V
IIL, IIH
0.1
µA
NOTES:
8. Limits established by characterization and are not production tested.
9. Dropout voltage is measured as VIN - VO, when VO is 4% lower than the value of VO
10. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization
and are not production tested.
Typical Operating Performance
40
T = ROOM TEMP
T = +45°C
45
T = +85°C
QUIESCENT CURRENT (µA)
QUIESCENT CURRENT (µA)
45
35
30
25
T = 0°C
20
15
T = -25°C
T = -40°C
10
5
0
1.5
2.5
3.5
4.5
INPUT VOLTAGE (V)
T = +45°C
T = 0°C
20
15
T = -40°C
T = -25°C
10
5
1.5
1.90
40
2.5
3.5
4.5
INPUT VOLTAGE (V)
5.5
+25°C
+85°C
1.85
30
T = 0°C
20
T = -40°C
T = -25°C
10
1.80
-40°C
1.75
1.70
0
-10
3.5
25
1.95
T = +85°C
Vo (V)
QUIESCENT CURRENT (µA)
T = ROOM TEMP
30
FIGURE 3. QUIESCENT CURRENT vs INPUT VOLTAGE
(VOUT = 1.85V)
FIGURE 2. QUIESCENT CURRENT vs INPUT VOLTAGE
(VOUT = 0.9V)
50
35
0
5.5
T = +85°C
T = +45°C
T = ROOM TEMP
40
1.65
4.0
4.5
5.0
INPUT VOLTAGE (V)
5.5
FIGURE 4. QUIESCENT CURRENT vs INPUT VOLTAGE
(VOUT = 3.3V)
FN7845 Rev 3.00
December 20, 2012
6.0
1.60
0
50
100
150
Io (mA)
200
250
FIGURE 5. LOAD REGULATION vs TEMPERATURE
(VOUT = 1.85V)
Page 6 of 12
300
ISL9021A
Typical Operating Performance (Continued)
3.5
2.00
1.95
1.90
3.4
+25°C
1.80
+85°C
Vo (V)
Vo (V)
+85°C
3.3
1.85
1.75
+25°C
-40°C
1.70
1.65
3.2
-40°C
3.1
3.0
1.60
2.9
1.55
1.50
2.5
3.5
4.5
5.5
2.8
6.5
0
50
100
3.50
1.05
3.45
1.00
3.40
+85°C
3.30
3.25
-40°C
0.75
0.70
3.05
0.65
4.5
5.0
+25°C
+85°C
5.5
6.0
-40°C
0.80
3.10
4.0
300
0.85
3.15
3.00
3.5
250
0.90
Vo (V)
Vo (V)
0.95
+25°C
3.20
200
FIGURE 7. LOAD REGULATION vs TEMPERATURE (VOUT = 3.3V)
FIGURE 6. LINE REGULATION vs TEMPERATURE (VOUT = 1.85V)
3.35
150
Io (mA)
VIN(V)
0.60
0
50
VIN (V)
100
150
200
250
FIGURE 8. LINE REGULATION vs TEMPERATURE (VOUT = 3.3V)
FIGURE 9. LOAD REGULATION vs TEMPERATURE (VOUT = 0.9V)
VIN = 2.7V
1.00
0.95
VOUT = 1.85V
+85°C
0.90
Vo (V)
COUT = 1µF
VOUT
+25°C
0.85
-40°C
0.80
0.75
0.70
3.0
IOUT
3.5
4.0
4.5
5.0
5.5
6.0
IOUT = 1mA TO 250mA
VIN (V)
FIGURE 10. LINE REGULATION vs TEMPERATURE (VOUT = 0.9V)
FN7845 Rev 3.00
December 20, 2012
300
Io (mA)
FIGURE 11. LOAD TRANSIENT RESPONSE
Page 7 of 12
ISL9021A
Typical Operating Performance (Continued)
VIN = 2.7V
COUT = 4.7µF
VOUT = 1.85V
VOUT
IOUT
IOUT = 1mA TO 250mA
FIGURE 12. LOAD TRANSIENT RESPONSE
FIGURE 13. ENABLE FUNCTION (VIN = 3.6V, VOUT = 1.85V,
COUT 1µF)
-20
-30
VIN = 4.5VDC + 50mVAC
COUT = 1µF
PSRR (dB)
-40
IO = 10mA
-50
-60
-70
IO = 0A
-80
-90
100
1k
10k
100k
1M
FREQUENCY (Hz)
FIGURE 14. POWER SUPPLY REJECTION vs FREQUENCY
FN7845 Rev 3.00
December 20, 2012
Page 8 of 12
ISL9021A
Functional Description
The ISL9021A is a high performance low-dropout regulator (LDO)
with 250mA sourcing capability. The extra low ground current
makes this part a good choice for handheld product applications.
The device also incorporates overcurrent, thermal shutdown,
reverse current protections, and soft-start features.
Thermal shutdown protects the device against overheating.
Soft-start limits the start-up input current surges. In some
applications, the output voltage may be externally pulled higher
than the input, or the input voltage could be connected to ground,
or connected to some voltage lower than the output side. The
ISL9021A features reverse current protection; that can block the
reverse current from output to input.
Enable Control
The ISL9021A has an enable pin. When EN is low, the IC is in
shutdown mode. In this condition, all on-chip circuits are off, and
the device draws minimum current, typically less than
0.1µA(typ). Driving this pin high will turn on the device.
LDO Protections
The ISL9021A offers several protection functions, making it ideal for
use in battery-powered applications. The ISL9021A provides
short-circuit protection by limiting the output current at current limit
of 260mA (min). If the short circuit lasts long enough, the die
temperature increases, and the over-temperature protection circuit
will shut down the output. When the die temperature reaches about
+145°C, thermal protection starts to work with output being loaded
with at least 50mA. Once the die temperature drops to about
+110°C, the LDO will resume operation beginning with a soft-start.
FN7845 Rev 3.00
December 20, 2012
The ISL9021A’s reverse current protection is intended to block
reverse conduction if output voltage is higher than input voltage.
Input and Output Capacitors
The ISL9021A provides a linear regulator that has low quiescent
current, fast transient response, and overall stable operation
across the recommended operating conditions. A ceramic
capacitor (X5R or X7R) with a capacitance of 1µF to 4.7µF with
an ESR up to 400m is suitable for the ISL9021A to maintain its
output stability. The ground connection of the output capacitor
should be routed directly to the GND pin of the device, and also
placed close to the IC. Similarly for the input capacitor, usually a
1µF ceramic capacitor (X5R or 7R) is suitable for most cases, but
if a large, fast rising load transient condition is expected, a higher
value input capacitor may be necessary to achieve satisfactory
performance.
Board Layout Recommendations
A good PCB layout is an important step to achieve good
performance. It is recommended to design the board with
separate ground planes for input and output, and connect both
ground planes at the GND pin of the IC. Consideration should be
taken when placing the components and routing the trace to
minimize the ground impedance, and keep the parasitic
inductance low. Usually the input/output capacitors should be
placed as close to the IC as possible with a good ground
connection.
Page 9 of 12
ISL9021A
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make
sure you have the latest revision.
DATE
REVISION
CHANGE
December 17, 2012
FN7845.3
Added evaluation boards and ISL9021AIIUZ-T to “Ordering Information” on page 3.
December 2, 2011
FN7845.2
Changed CSP package dimension from “2mmx2mm” to “0.975mmx1.155mm” on page 1 to page 3.
October 7, 2011
FN7845.1
Updated “Ordering Information” on page 3 by adding ISL9021AIRUYZ-T and ISL9021AIRUYZ-T7A parts. Made
corrections to part markings and added -T7A parts.
May 27, 2011
FN7845.0
Initial Release
About Intersil
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FN7845 Rev 3.00
December 20, 2012
Page 10 of 12
ISL9021A
Package Outline Drawing
L6.1.6x1.6
6 LEAD ULTRA THIN DUAL FLAT NO-LEAD COL PLASTIC PACKAGE (UTDFN COL)
Rev 1, 11/07
2X 1.00
1.60
A
6
PIN 1
INDEX AREA
PIN #1 INDEX AREA
6
B
4X 0.50
1
3
5X 0 . 40 ± 0 . 1
1X 0.5 ±0.1
1.60
(4X)
0.15
4
6
0.10 M C A B
TOP VIEW
4 0.25 +0.05 / -0.07
BOTTOM VIEW
( 6X 0 . 25 )
SEE DETAIL "X"
( 1X 0 .70 )
0 . 55 MAX
0.10 C
C
BASE PLANE
(1.4 )
SIDE VIEW
( 5X 0 . 60 )
C
SEATING PLANE
0.08 C
0 . 2 REF
0 . 00 MIN.
0 . 05 MAX.
DETAIL "X"
( 4X 0 . 5 )
TYPICAL RECOMMENDED LAND PATTERN
NOTES:
1. Dimensions are in millimeters.
Dimensions in ( ) for Reference Only.
2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994.
3. Unless otherwise specified, tolerance : Decimal ± 0.05
4. Dimension b applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
5. Tiebar shown (if present) is a non-functional feature.
6. The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 identifier may be
either a mold or mark feature.
FN7845 Rev 3.00
December 20, 2012
Page 11 of 12
ISL9021A
Wafer Level Chip Scale Package
(WLCSP 0.4mm Ball Pitch)
W2x2.4
2x2 ARRAY 4 BALL WAFER LEVEL CHIP SCALE PACKAGE
D
E
PIN 1
TOP VIEW
SYMBOL
MILLIMETERS
A
0.44 Min, 0.495 Nom, 0.55 Max
A1
0.190 ±0.030
A2
0.305 ±0.025
b
0.270 ±0.030
D
1.155 ±0.020
D1
0.400 BASIC
E
0.975 ±0.020
E1
0.400 BASIC
e
0.400 BASIC
SD
0.200 BASIC
SE
0.00 BASIC
NUMBER OF BUMPS: 4
Rev. 2 6/08
A2
A1
A
NOTES:
1. All dimensions are in millimeters.
b
SIDE VIEW
e ( D1 )
2
SE
e ( E1 )
1
B
A
b
SD
BOTTOM VIEW
FN7845 Rev 3.00
December 20, 2012
Page 12 of 12